Electrochemical battery packs may be used to energize electric machines in a variety of systems. For instance, output torque from an electric machine in the form of a traction motor may be used to power an input member of a transmission, such as in a hybrid or battery electric powertrain, a static powerplant, or other torque generating system. The electric machine may be an alternating current (AC) or direct current (DC) motor/generator device that draws electrical energy from or delivers electrical energy to the battery pack as needed. In turn, the battery pack may be recharged via a charging current supplied from an offboard power supply or via onboard regeneration. The battery cells store an electric charge until such a charge is needed, while a reverse reaction discharges the battery pack to deliver electricity to the electric machine. Charging and discharging currents are closely regulated by a controller so as to avoid excess powerflow with respect to the battery cells, which can overheat the battery cells and degrade the battery pack.